Local vibrator for concrete



March 4, 1958 N. ANDRIANI 2,825,533

LOCAL VIBRATOR' FOR CONCRETE Filed May 16, 1955 INVENTOR mgc OLA ANDRIANI ATTORNEY;

2,825,538 LOCAL VIBRATOR FOR CONCRETE Niccola Andriani, Rome, Italy Application May 16, 1955, Serial No. 508,660 Claims priority, application Italy May 14, 1954 Claims. (Cl. 259-1) The present invention relates to a local vibrator for concrete, the tool of said vibrator being inserted into the concrete and left therein.

The usual vibrating devices are directly applied to the outer side of the form. However said devices in general produce an inadequate vibration which does not reach the central zone of the concrete mass which is to be vibrated, nor does the vibration reach the opposite and farthest zone of said mass. If the intensity of vibration is increased in order to reach the aforecited central or farthest zone, this increase, which must be made near to the form, affects the structure of the concrete.

There are also known vibrators which are inserted within the mass of the concrete and provided with a remote control consisting either of a flexible shaft or a pneumatic or hydraulic drive system. However said systems produce some difliculties when the vibrating tool is to be recovered, and they are not suitable for operation deep inside the mass.

The object of this invention is that of obviating the aforementioned drawbacks by a local vibration system which permits the vibrator tool to be left within the vibrated mass, said tool being inexpensive and such as not to damage the features of the casting.

It is thus possible to use dry concretes, containing a minimum percent of water, the advantages of which are well known.

The vibrators according to this invention are completely embedded in the concrete, while the vibrating apparatus is arranged outside the form, so as to permit the aforementioned possibility either of recovering said tool or leaving it Within the concrete when the vibration has been completed. In the vibrating device according to this invention, the vibrating tool is inserted into the form through holes pre-disposed in the elements forming the form, while the vibrating device is fixed outside said form.

The vibrating tool can have different shapes, depending on the dimensional and qualitative features of the mass to be vibrated and according to the magnitude and to the frequency of the vibrations to be used. Generally said tool has one or more blades Welded to one another at different angles, so as to ensure sufilcient rigidity for the transmission of the vibrations and also for minimizing the occupied volume when the tool is to be abandoned after its use instead of being extracted through the insertion hole after the vibration has been completed.

One preferred form of embodiment could be that of an outer vibrator, operated in any manner suggested by the art and applied to the outside of the form, either directly or by means of an independent support.

This invention will be better understood from the following specification taken in connection with the drawing wherein is shown a detail cross-sectional view of a form provided with the vibrating device according to this invention.

With reference to the drawing, 1 is the form which can be made either of wood or metal, said form being provided with an aperture 2 for the application of the vibrating apparatus.

Said vibrating apparatus comprises first the vibrating device 3. Said device needs is provided with a number of spokes or radial projections 4 for securing the device to the form by means of bolts (not shown in figure), so that the working vibrating shaft of the device 3 registers with the aperture 2 in the form 1.

The vibrating shaft projecting from the device 3 comprises a cylindrical portion 5, the outer surface of which is preferably smooth, and an extending portion 6, this latter being cylindrical and preferably of less diameter than cylindrical portion 5 and threaded on its outer surface.

On the smooth portion 5 can be positioned a sleeve 7, the length of which corresponds to the thickness of the form, the inside diameter of said sleeve being such that it will allow the vibration of the vibrating shaft. Said sleeve is also provided either with a circular flange or with a number of spokes 8 allowing the sleeve to be applied to the form. The end of the sleeve 7 which corresponds to the inner surface of the form is provided with one or more teeth 9 (only one of which is shown in figure) the use of which will be later described.

On the threaded end 6 of the vibrating shaft can be threadedly fitted a sleeve iii to which is connected the vibrating tool or blade 11, formed by a metallic blade reinforced by a central rib, so as to have the necessary rigidity for the vibration; also, said tool can be formed by a star shaped section iron. The edge of the sleeve 1% turned towards the inside of the form is provided with a slot 12 into which tooth 9 fits so as to prevent the parts from rotatin' relative to each other when the sleeve 1% abuts the sleeve '7.

Having thus described the parts of this apparatus, as far as their embodiment is concerned, the operation of said apparatus is as follows:

The unit is predisposed for operation when the device 3 is still spaced apart from the form. The sleeve 8 is fitted on the cylindrical portion 5 of the working shaft and then sleeve iii is threaded on the threaded end 6 of said shaft. Then, the vibrating tool 13 is inserted through the aperture 2 of the form I, obviously at a level above that attained by the concrete inside the form. The insertion continues until the spokes 4 of the device 3 come into contact with the outer surface of the form. By causing the sleeve 7 to slide on the shaft 5', it is inserted through the aperture 2 until its front end con tacts the sleeve it the tooth 9 of the sleeve 7 being thus inserted into the slot 12 of the sleeve iii. In this condition, when the annular flange d, or the spokes which replace said flange, have been fixed on the form 1, the unit is ready for operation.

The form is filled until the level of the vibrating tool 11 has been exceeded by the suitable amount, and the concrete is vibrated. When the vibration has been carried out, if the concrete is still fluid to a sufficient extent to allow the vibrating tool to be extracted, if this is desired, the unit is extracted as a whole, by disconnecting both the flange 3 and the spokes 4. On the contrary, if either the concrete has a compactness which will not permit the tool 11 to be extracted, or it is deemed not suitable to extract said tool, it is abandoned within the vibrated mass and the driving portion is disconnected by disengaging the spokes 4 from the form 1 and leaving the annular ring 8 engaged with the form. in this way the engagement between the sleeve 7 and the sleeve It) is maintained so that this latter is prevented from rotating by the tooth 9 which is inserted within the slot 12. Then the vibrating device 3 is rotated so as to unscrew the threaded portion 6 from the sleeve 1%, so as to allow the vibrating device to be extracted together with its i forni, a vibrating tool insertable shaft, while-the vibrating tool 11 and sleeve are -abandoned'within the concrete.

This way it is possible, for instance to vibrate a'pillar "of concrete at different heights obtaining a remarkably better result while thecost of the vib'r ating tool'abandoned having an aperture therein, -a vibration producing mea'ns which-can be placed against-the outside of said concrete said concrete form '"necting said tool to the-vibratibn-producing means and permitting disconnecting of said tool from 'said vibration I V fproducing means. 5

- "'2. ;A' concrete vibratopcomprising a; concrete-form 5 having an aperture therein, a vibration producing means which "can be placed against the outside 0f said concrete form and havin g a threaded end thereon sufiiciently long to extend through the form, ;a vibrating 'tool insertable 7 through the aperture in said concrete form for vibrating concretexwithin said form, connecting -means attached to said vibrating tool into which connecting means said throughthe aperture in. forvibrating concrete 'withinsaid f orrn, and means 'between'said vibration producing means and said vibrating 'tool flush with the 7 surface of the Yconcrete on the inner face 'of the concrete form for conthreaded end is threaded, said connecting means being v ,flush withthe surface of the concrete on the inner face of the concrete tor m, and sleeve means 'inser'table into said form for retaining said connecting means in saidconcrate-when said vibration producing means is unscrewed from said connecting means. e V

3. A concrete vibrator comp sing a-concreteform havingan'aperture therein, a vibration-producing means which can be placed against the outside -of-said concrete form-and having a threaded end thereon'suificiently long to extend through the form, a vibratingtoolinsertable through theaperture in said concrete form for vibrating concrete 'within the form, a connecting sleeve attached to said vibrating tool and having a threaded boretherein means,-the end of said connecting sleeve opposite the vibrating tool being flush with the concrete on the inner surface of the form, and a retaining sleeve with a diameter-at least as small as the diameter of said'connecting sleeve and having a bore therethrough sufliciently large to receive the threaded end of said vibration producing means, said retaining sleevebeing 'insertable.

through-the form, 1

Q4.A concretevibrator comprising a concrete form having'an'aperture therein, a vibration producing means which can be placed against the outside of'sa'idconcrete' posite the inner surface of the ton-1i; and aretaifiing' sleeve with a diameter at least as small asbthe diameter of said connecting sleeveand having ahoretherethrough suificiently i large to receive theithreadedend of said vibration pro- 2 5 concrete within the form,-

"asgp ass, 5 Y

form and having a threaded end thereon suiiiciently long to-extend through theform, a vibrating tool insertable through the aperture in said concrete form 'for vibrating concrete Within-the form, attached to'said vibrating tool and having a threaded bore therein receiving said threaded, end on' said vibration producing means, the end o f isaid connecting sleeve opthe vibrating tool being flush withtthe concrete on ducing ,means, said retaining sleeve being insertable through "the "form, a

meeting sleeve for preventing rotation of said connecting sleeve relative to saidretaining sleevei.

5; -A" c Zncr'ete 7 vibrator compr sing a having an aperturetherein, a vibratidn producing means lform'and hav'ng a I b 4 H to egitend through the -form, a vibrating tool insertable through the aperture in said concretejormjtorjibratingto said fvibratin' tool H receiving said threaded 7 end on said' yibration producing 'means,fthe end of said connecting sleeve opposite. the vibratingtool being flush with the concrete on the; inner surfacejof th'eflfor' n', and-aretainingsleeve with a diameter at-least as small as thediameter of said connecting sleeve and having a bore therethrloiighi sufliciently; large torereceiving said threaded endon said vibration producing 'ceive the threaded end of-said vibration gproducing neans,

said retaining sleeve being insertable through the forrn,

a flange on said retainin V against rotation in the form, sleeve, said connecting sleeve receiving said teeth! 4 hen ea-ease having recesses thereincfor References Citedin h tile oi tliis patent f UNITED sT 'rEsPAIENIs 1,770,154 Day, July; 8;j1930 91 39 iQkQP e-.-e--l---re--s- .'Mayiii), 1 9,33 1,970,740 Day Aug-21,1934 2,019,937 Staples ;Nov.j=5,1935

2,055,514 Whiti ng 7 ;Sept; 29,1936 I 2,293,962 Baily Aug. ;2-s ,-1942 a j 'VFOREIGNIIPATENTSZ a 1 5 1,005 Denmark Nov, .27 5 2 19 3 5 113,857 5 Sweden Apr; ,17; ,945

a connecting sleeve flange on said retaining sleeve for securing said sleeve against r tation in the form, and 7 means on said retaining sleeve cooperating with said con 5 a -s i g sl ev mask and having a threaded bore therein g sleeve for securing saidsleeve I 1. ass-B 1 19 5 

